Ext.regModel('Article', {
    fields: [
        {name: 'title',  type: "string"},
        { name: 'pubDate', 'type': "date" },
        {name: 'imageSrc',   type: 'string'},
        {name: 'content', type: 'string'}
    ],
    proxy: {
        type: 'sessionstorage',
        id: 'article-app-sessionstore'
    }   
});